Yo, Maybe you should be able to by cubes (For the Factory and Blueprints) should be able to be bought for gems too? 1 Gem = 1 Cube or some sort of thing, cause the gems aren't that great to use in game (Unless your forced to cause you about to die) and all the lab upgrades don't take that long to actually get
 "The Perfect Tower"){kind=icon}
 "Knightmare Tower"){kind=icon}
You should check out the development build ;) You can spend gems inside the factory.